The present invention will find application for anesthesiological support of an operative interference involved in a stomatological manipulation, i.e., preparation of hard dental tissues for a fixed partial denture, as well as in tooth filling and in operative treatment of caries.
An analgesic effect of a pulsed electric current is based on activation of the antinociceptive organism's system, which causes a complete or partial blocking of nociceptive impulses' conduction. A distinguishing feature of such an analgesic technique resides not only in a reduced patient's appreciation of pain but also amelioration of his/her psychoemotional state and normalization of the patient's physical reactions.
One state-of-the-art device for electrostimulation of a patient's tissues is known to be extensively used currently. (SU, A, 1,034,650), said device comprising a low-frequency current pulse generator, a high-frequency current pulse generator, the outputs of both being connected to the inputs of an electric pulse front discriminator, which is a shift register. The device comprises also a pulse shaper based on series-connected a first flip-flop and an AND gate.
The output of the low-frequency generator is also connected to the input of the first flip-flop.
The output of the AND gate is connected to the input of a current amplifier, while the output of the current amplifier is connected to the primary winding of a transformer, and the secondary winding of the transformer is connected, via the shift register, to electrodes. The input of a second pulse shaper is connected to a resistor, while the output of the pulse shaper is connected to a first input of a second flip-flop. The other input of the second flip-flop is connected to the output of the high-frequency current pulse generator, while the output of the second flip-flop is connected to the other input of the AND gate. The high-frequency pulse generator produces a train of electric stimuli (pulses) of a predetermined adjustable duration and repetition frequency. The output voltage of the second flip-flop gates the pulses at the input of the AND gate so that those pulses are passed at the output of the AND gate whose duration is not in excess of a value preset by the low-frequency generator. The electric stimuli arrived from the output of the AND gate, are applied to the current amplifier, which is loaded with the transformer. The amplitude of electric pulses delivered by the transformer secondary is increased with an increase in the duration of the voltage pulses applied to the transformer primary, whereas the electric pulses from the transformer secondary are delivered to the electrodes.
To provide an analgesic effect in preparation of hard dental tissues the active electrodes of the device are applied to the skin of reflexogenic zones, such as, e.g., the auricular concha, while the passive electrodes of the device are applied to the patient's facial skin close to the area of an intended stomatological interference.
In a given device a definite pulse repetition frequency and duration are set by manual adjustment of a variable resistor, while the intensity of tissue electrostimulation at the place of application of the active electrodes is preset according to patient's subjective sense of intense vibration under the electrodes due to electric current flowing therealong. As a result of the electrostimulation process the patient's pain sensitivity threshold is increased and the intensity of vibration sense is reduced or disappears altogether. To provide an analgesic effect adequate to the patient's painful sensations during an operative interference the dentist increases the amplitude of the current pulses by manual adjustment of the variable resistor in order to increase the intensity of electrostimulation and to attain the original sensory acuity of electrostimulation. To provide an analgesic effect adequate to the intensity of the patient's painful sensations, it is necessary to correct the intensity of electrostimulation five or six times for 25 to 30 minutes by manual adjustment of the variable resistor.
Thus, the intensity of anesthesiologic electrostimulation depends on patient's subjective sensation, which is influenced by his/her psychoemotional state, and on the practical skill and experience of the dentist involved.
Manual adjustment in the course of electrostimulation results, in a prolonged period of time required for attaining an analgesic effect, affects adversely the adequacy of electroanalgesic effect to patient's painful sensations during surgery. The parameters of effective electric pulses, i.e., amplitude, repetition frequency and duration are not concerned with an individual dynamics of increasing the patient's pain sensitivity threshold. The device fails to provide prognostication of an analgesic effect of electrostimulation. Inadequacy of the analgesic effect to patient's painful sensations during surgery can be determined only in the course of a stomatologic interference according to patient's painful sensation.